基于相关算法的海缆埋深检测性能分析

基于信号和噪声统计不相关特性,提出了相关算法在海缆埋深检测中的新应用,并结合IIR（无限脉冲冲击响应）滤波算法进行了分析比较。当幅值为1 V的25 Hz探测信号分别受到幅值为100 V的20.15 Hz,24.45 Hz强噪声干扰时,相关算法滤波后得到的归一化幅值分别为1.185和5.870,而IIR滤波算法得到的归一化幅值为1.42和9.32。仿真结果表明,海缆探测中相关算法优于IIR滤波算法。     

差分吸收光谱检测H2S气体的反演算法

传统差分吸收光谱法(DOAS)对于H2S气体浓度检测原理简单,检测精准,反应速度较快,但在低浓度、光程较短的环境中会产生较大的误差。本文在传统的差分吸收算法的基础上,采用遗传算法对低浓度H2S气体进行反演,但遗传算法容易发生过早收敛,从而陷入局部最优,因此设计了灾变优化后的遗传算法对H2S气体浓度进行反演。结果表明,该方法对低浓度H2S气体有较高的测量精确度,与传统的差分吸收光谱法结合可得到更宽的检测范围。     

Lightweight Triboelectric Nanogenerator for Energy Harvesting and Sensing Tiny Mechanical Motion

Triboelectric nanogenerators (TENGs) have shown exciting applications in mechanical energy harvesting and self‐powered sensing. Aiming at commercial applications, cost reduction and simplification of TENG structures are of great interest. In this work, a lightweight TENG based on the integration of polymer nanowires and a carbon sponge, which serves both as the substrate and an electrode, are reported. Because of the low density of the carbon sponge and the filmy nanowires, the device exhibits a total mass of less than 0.1 g for a volume of 12.5 cm³ and it produces a short‐circuit current of 6 μA, open‐circuit voltage of 75 V, and a maximum output power of 0.28 W kg^?1 under light finger tapping. The device can linearly measure the acceleration at a detection limit down to 0.25 m s^?2 and for a detection range from 0.25 m s^?2 to 10.0 m s^?2.     

All-digital gated ring oscillator $$\Delta \Sigma$$ modulators

This paper presents all-digital time-mode \(\Delta \Sigma\) modulators. The proposed modulators consist of a voltage-to-time integrator, a seven-stage gated ring oscillator functioning as a 3-bit quantizer, and seven digital differentiators. A detailed analysis of the nonlinear characteristics of the modulators is provided. Designed in IBM 130 nm 1.2 V CMOS technology with a 100 mV 100 kHz sinusoidal input and a 4.4 MHz frequency clock, the first-order modulator provides 47 dB SNR over 0–150 KHz bandwidth while consuming 1.1 mW while the second-order modulator provides 55 dB SNR over the same bandwidth while consuming consumes 1.45 mW.     

基于.NET平台的Word数据自动交换管理技术应用

基于.N ET的Word自动化解决方案为企业自动化应用提供了基础平台,本文分析了解决方案的对象模型技术,并对几个常用的Word对象的原理进行了详细介绍,并用实例对其使用方法进行了说明,这对实现Word数据管理自动化具有一定的指导意义。     

Regulating the Water Molecular in the Solvation Structure for Stable Zinc Metal Batteries

Rechargeable aqueous zinc batteries are promising energy storage devices because of their low cost, high safety, and high energy density. However, their performance is plagued by the unsatisfied cyclability due to the dendrite growth and hydrogen evolution reaction (HER) at the Zn anode. Herein, it is demonstrated that the concentrated hybrid aqueous/non-aqueous ZnCl₂ electrolytes constitute a peculiar chemical environment for not only the Zn-ions but also water molecules. The high concentration of chloride ions substitutes the H₂O molecular in the solvation structure of Zn²⁺, while the acetonitrile further interacts with H₂O to decrease its activity. The hybrid electrolytes both inhibit the dendrite formation and HER, enabling an ultrahigh average Coulombic efficiency of 99.9% in the Zn||Cu half-cell and a highly reversible Zn plating/stripping with a low overpotential of 21 mV. Using this hybrid electrolyte, the Zn||polytriphenylamine (PTPAn) full cell deliveres a high discharge capacity of 110 mAh g⁻¹, a high power density of 9200 W kg⁻¹ at 100 °C and maintains 85% of the capacity for over 6000 cycles at 10 °C. This study provides a deep understanding between the solvation structure and columbic efficiency of Zn anode, thus inspiring the development for stable Zn batteries.     

Analysis of User＇s Weight in Microblog Network Based on User Influence and Active Degree

Based on user’s in-degree distribution, traditional ranking algorithms of user’s weight usually neglect the considerations of the differences among user’s followers and the features of user’s tweets. In order to analyze the factors which impact on user’s weight, under the analysis of the data collected from SINA Microblog network, this paper discovers that user influence and active degrees are the dominant factors for this issue. The proposed algorithm evaluates user influence by user’s follower number, the influence of user’s followers and the reciprocity between users. User’s active degree is modeled by user’s participation and the quality of user’s tweets. The models are tested by different data groups to confirm the parameters for the final calculation. Eventually, this paper compares the computational results with the user’s ranking order given by the SINA official application. The performance of this algorithm presents a stronger stability on the fluctuant range of the value of user’s weight.     

EPON+EoC技术在HFC网络建设中的应用

随着"三网融合"的逐步推进以及居民对电视节目的多样性的需求,广电有线网络也逐渐由单向传送广播电视传统业务向宽带业务等多种综合业务发展。在这进程中,EPON+EoC技术日趋成熟,本文简述了什么是EPON接入方式,什么是EoC调制技术,并结合实际,阐述了如何利用EoC技术充分利用楼内现有的同轴电缆资源,完成双向网络改造,如何利用EPON+EoC组网方式开展多种综合应用。     

分布式声传感器阵列校准方法综述

分布式声传感器阵列在军事侦察、公共安全监控和人机交互等领域应用广泛.但时钟异步、频率响应失配和节点位置未知问题严重影响后续基于分布式声传感器阵列的语音处理算法的性能,因此近年来学者们热衷于研究校准这三类阵列失配问题的方法.首先,本文介绍了导致分布式声传感器网络各类失配问题的原因和三类问题解决的先后顺序.然后,将现有的解...     

一种基于预测模式的H.264视频信息隐藏算法

提出了一种基于帧内预测模式调制的H.264视频信息隐藏算法。在模式选择过程,通过调制I帧亮度的4×4块的预测模式实现信息隐藏。通过引入嵌入/提取矩阵,使得在修改一个4×4块的预测模式时,能够嵌入3比特信息。在信息提取过程,不需要原始视频,也不需要完全解码,只需对帧内预测模式解码即可。实验结果表明,本文算法能大幅提高信息隐藏容量,且保证了视频感知质量,对比特率变化影响不大。